Thank you Elwyn, I will take a look at those links.
Both fathers, John Downey (Snr) and John Kelly would appear to be alive judging by the marriage certificate of John and Mary in 1865 at Kilkeel.
When John Downie died in 1908, the Scottish record lists his father as deceased and occupation as Fireman - which makes me think he may have also been involved in the Iron industry (like his son) somewhere in Scotland or England, but haven’t found a record for that hunch.